The present invention is directed to an electronic system for monitoring the coupling of a trailer to a trailer hitch assembly that is mounted on a truck chassis and, more specifically, to an electronic system that indicates whether the trailer is properly coupled to the trailer hitch assembly.
An electronic coupling control system for a vehicle trailer hitch assembly is described in U.S. Pat. No. 5,861,802, entitled xe2x80x9cFIFTH WHEEL HITCH COUPLING CONTROL SYSTEMxe2x80x9d to Hungerink et al., which is assigned to the assignee of the present invention and is hereby incorporated herein by reference. U.S. Pat. No. 5,861,802 discloses an electronic coupling control system that includes a trailer proximity sensor for sensing when a trailer is in the proximity of the hitch assembly, a kingpin sensor for sensing the presence of a trailer kingpin in a hitch plate throat and a lock sensor for sensing when the locking mechanism is locked in a secured position.
U.S. Pat. No. 5,861,802 also discloses an indicator located within the vehicle for providing trailer hitch assembly coupling status information to a driver of the vehicle. A control circuit is coupled to the trailer proximity sensor, the kingpin sensor, the lock sensor and the indicator. These sensors are utilized by the control circuit to inform a driver when a trailer is in close proximity to the trailer hitch assembly, when the trailer kingpin is positioned in the hitch throat and when the locking mechanism is in a locked position. The electronic coupling control system also includes an interface for coupling a control input, of an electrical control system of the vehicle, to the electronic coupling control system. The electronic coupling control systen is also capable of performing various self-diagnostic routines to ensure proper operation of the system, when the vehicle ignition is turned on.
While the electronic coupling control system of U.S. Pat. No. 5,861,802 advantageously provides some information to a user, it would be desirable for an electronic control coupling system to reliably provide additional information to a user.
An embodiment of the present invention is directed to an electronic system for monitoring a trailer hitch assembly, which includes a hitch plate with a throat for receiving a kingpin of a trailer and a locking mechanism for locking the kingpin in the throat. The system determines whether the trailer hitch assembly is properly coupled to the trailer and includes a trailer sensor, a lock sensor and a control circuit. The trailer sensor senses the position of the trailer relative to the trailer hitch assembly. The lock sensor senses the position of the locking mechanism and the control circuit is coupled both to the trailer sensor and the lock sensor. The control circuit determines whether the trailer hitch assembly is properly coupled to the trailer by taking into account the sequence in which the trailer sensor and the lock sensor sense the respective positions of the trailer and locking mechanism and masks an output of the lock sensor for a first predetermined stabilization period after the control circuit initially determines that the trailer hitch assembly is properly coupled to the trailer.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.